Hey there Zhenboy, nice to hear from you again dude!
Got it connected and have loaded Tiger on it. Annoyingly enough it came with Panther to Tiger upgrade however I just downloaded Tiger off the net haha

(either way I've paid for it...)
Things I've noticed to be sluggish:
--GFX, Not the greatest with the RSS Screensaver, what to expect with 32MB of on board VRAM.
--HDD Speed - not the greatest either
However I admit I expected these slight slow downs, however for basic use it is brilliant, I really like it.
It is no Power Mac but is good enough for most things - I'm planning on installing this in my car (as a carpooter
lol). Will see how that goes
Opening it: It has tabs on the insides like the iPods do - so yea you CAN open it, look online for a few guides.